LOS ANGELES – When Saturday began, 19 of the 31 first-round selections from Major League Baseball's first-year player draft remained unsigned. That number could decrease soon, as the Arizona Diamondbacks are "very close" to signing first-rounder Touki Toussaint, according to General Manager Kevin Towers.

The Diamondbacks took Toussaint, a raw but well-regarded high school pitcher from Florida, with the 16th pick a week ago. He is committed to Vanderbilt.

"I think it's some minor things that (amateur scouting director) Ray (Montgomery) is still working on with his adviser," Tower said. "Pretty optimistic we'll get something done here shortly. Once we do that then we're going to want to make sure we get him checked out medically to make sure he's healthy."

Toussaint is one of two Arizona picks from the first 10 rounds unsigned, along with fifth-round pitcher Mason McCullough. Vanderbilt is normally a difficult school to draw prospects away from, but two other Diamondback picks in the top four rounds — pitcher Cody Reed and infielder Isan Diaz — were Commodore commits who went pro instead.

It helps that the Diamondbacks have some wiggle room in the budget.

Arizona began the draft with $7,228,300 available to spend on Rounds 1-10 before incurring overage penalties, and the 16th overall selection was assigned a slot value of $2,338,200.

Because the Diamondbacks signed several high picks under slot value, they could have as much as $321,800 extra to throw at Toussaint.

"(Montgomery) protects himself just in case it may take a bit more money than slot," Tower said. "But I think going into he had a pretty good idea within a very small ballpark what it probably took to get Touki done."

Gibson's reasoning was that fellow shortstop Didi Gregorius needs regular playing time to make his call-up from Triple-A worthwhile and that second baseman Aaron Hill is on the verge of breaking out of his seasonlong slump.

"It's tricky and hard to do," Gibson said. "Sometimes you're going to have to go against the numbers to get everyone their playing time."

The move seemed to pay off early somewhat, as Gregorius hit a leadoff double to start the game and scored on Paul Goldschmidt's home run.

Cahill reaction

Like his manager, Towers isn't concerned about the poor numbers posted by demoted starter Trevor Cahill in his first minor-league outing with Class A Visalia.

"I'd be more concerned if there's similar results a month from now," Towers said. "He was erratic similar to what we've seen. I didn't think just by sending him down all of a sudden he was going to start pounding the zone."

Notable: Arroyo is 5-2 with a 2.71 ERA in his past nine starts, although he maintains he hasn't been pitching at full health. His sinking fastball is averaging 86 mph after it sat around 88 mph last season. In 15 starts against the Dodgers, he is 4-4 with a 3.75 ERA. … Beckett has been strong all year and pitched his first career no-hitter on May 25 against the Philadelphia Phillies. He's striking out 8.7 batters per nine innings, his most since 2008.